Mold for making plastic coil with straight leads



MOLD FOR MAKING PLASTIC con. WITH STRAIGHT LEADS C. A. REDMER Jan. 14,1964 2 Shqets-Sheet 1 Filed Dec.

INVENTOR. CARL A. REDMER ATTORNEY MOLD FOR MAKING PLASTIC COIL WITHSTRAIGHT LEADS Jan. 14, 1964 c. A. REDMER Filed Dec.

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INVENTOR.

CARL A. REDMER. BY

ATTORNEY United States Patent 3,117,344 MULD FOR lvlAKlNG PLASTIC COILWITH STRAIGHT LEADS Carl A. Redmer, Cranford, N.J., assignor to Carmergndustries, Inc., Parsippany, NJ, a corporation of New ersey Filed Dec.15, HQ, Ser. No. 159,519 3 Claims. (Cl. 18-19) This invention relates toa mold for producing a siphon attachable to a tapper valve of a keg,such as an aluminum beer keg, and to the process of making same. Morespecifically it relates to a method for producing a coiled plasticsiphon having straight extending ends, and to a mold for producing saidsiphon.

In recent years, there has been a demand for a sanitary exible siphoncapable of attachment to the tapper valve of an aluminum beer keg, forexample, which would retain its original shape after numeroussterilizations at scalding temperatures. Such a siphon has been soughtby makers of kegs for several years, and many plastic processors andother technicians have tried in vain to effect a satisfactory solutionto the problem.

Among the requirements for such a siphon are the following: In the firstplace, it must be a small flexible tube of exact length, e.g., 25inches, plus 0.25 inch minus zero inch, for a specific keg application,and such length must be compacted into a length of about 6% inches. Thereason for the overall tube length limitation is that it must draw 13ozs. of beer in seconds, without exces sive foam, and research hasdetermined that the aforesaid specified length will accomplish this.However, since the distance from the tap valve connection to the centerof the barrel bottom is about 6 /4 inches, this 25" length must becompacted (e.g., by coiling) to the 6 /4" distance.

The next requirement is that the tube, when free, at all times maintaineach end (about 2 /8") extending from the coil straight horizontally andin alignment in spite of repeated sterilization heats of 210 F.,followed 10 seconds later with passage therethrough of beer at 32 F.When in use, one straight end of the tube is attached to the tappingvalve connection, while the other (extending) end must lie fiat on thekeg bottom to insure drainage of the entire contents of the keg.

Another requirement is that the coil be essentially round (i.e.,unilattened) in order to effect the required passage of beer in thespecified time, and the coils must be separated (about from each other,since the Government considers closed coils as unsanitary because theytend to breed bacteria. Furthermore, the outside diameter of the coilmust not exceed 1.000 inch diameter- *0.060, since it must be insertedinto and removed from the keg tapping hole.

A still further requirement is that the plastic used for the tubing beof natural color, odorless, tasteless, and must hold its shape at 200 F.for 2 minutes and at 32 F. for storage. The only plastic materialapproved by the Government for such application is a nylon (polyamide)plastic sold commercially as Zytel 31, or its equivalent. According toits specifications, this material is recommended for temperatures of270-300 F. of continuous use.

According to the present invention, these requirements have been met andthe problem has been successfully solved commercially by the use of thenovel process and forming die or mold described herein. Thepredetermined length of tubing of specified polyamide is mounted on thenovel forming mold and baked under controlled stabilization conditions,and then cooled and the formed coil is removed from the mold, ready foruse.

The invention will be more readily understood by reference to theaccompanying drawing in which FIGURE 1 3,1 $7,344 Patented .lan. 14;,1964 depicts, on a greatly reduced scale, a side cross-sectionalelevation of an aluminum keg in which is mounted a tapping valve toWhich is attached a siphon coil of the present invention. FIGURE 2presents an enlarged side elevational view or" a siphon coil of thepresent invention, as attached to a tapping valve of the keg. FIGURE 3illustrates a side View of the forming mold in which the plastic siphontubing is indicated in broken lines, while FIGURES 4 and 5 show top andbottom end views, respectively, thereof. FIGURE 6 shows a side view ofthe mold with the upper split covering end removed and turned over theexpose the two bottoms thereof. Similar numerals refer to similar partsin the various figures.

Referring again to the drawing, numeral ill represents generally theplastic siphon coil having one end 11 inserted ti htly into mounting 12of tapping valve 13 in the head 14 of aluminum beer keg 15. It will benoted that free end 16 of coil 169 is disposed directly on sidebottom 17of keg 15.

Coil Ill is made by taking a straight length of specified nylon tubing,say of 0.138"/O.128" internal diameter and 0.025 wall thickness, andmounting it on the forming mold, indicated generally as 13. Mold 18comprises a length 19 of solid round core rod, preferably of anodizedaluminum of, say 6%" length, the center portion (for about 2%") of whichis provided with a continuous helical fin 2i), projecting about fromcore rod 19, and having a pitch of about 4 turns per inch. Fin (or fins)20 is (or are) about in thickness.

Core 19 has, mounted on its top end, a split cylindrical cover,indicated generally as 21, and, on its bottom, a single piece sleevecover 22. Cover 21 consists of piece 23 having hold 24 through whichpasses screw 25 fitting into threaded hole 26 of the core. Screw 25 thusserves to removably attach piece 23 to core 19. The other piece 27 ofsplit cover 21 has an angular-shaped key 28, attached to the inside ofpiece 27 by set screw 29, which key rides partially in angular keyway 39in end 19 of core 19. Keyway 30 is about wide and /8" deep at end 19',its vertical taper being such that it reaches the edge of core 19 about1%" from end 19'. Cover 21 is about 2" long, and key 23 is deep enoughto engage in keyway 30, but is short enough to leave free space 31through which straight end 11 of tubing l9 may pass freely.

Bottom end cover 22 on core 19 also is provided with an inner key 32',held onto cover 22 by set screw 33, and designed to ride in a portion ofkeway 34 cut into end 19" of core 19. Keyway 32 also is about deep atend 19" and it reaches the peripheral edge of core 1? about 1%" from end1;". Key 32 projects about at end 1W, and is tapered to allow passage,through free space 35, of straight end 16 of coil ll).

Fins 20 are about di apart, and ends 24) and Zll thereof are featheredso as to make a line contact with inner edges 21 and 22; of covers 21and 27', respectively. Rounded entrance slots 36-36 are provided at theinner edges of covers 21 and 22, respectively, immediately over emergingterminals 30' and 34 of keyways 3t? and 3 5-, respectively, to permiteasy entry of tubing 19 into key- Way spaces 31 and 35, respectively,and also to provide a /2" radius at end junctures Ill and 16',respectively, of siphon coil 10.

Coil 19 is formed by first removing piece 27 of cover 21, and theninserting end 16 of the pre-cut tubing piece through slot 37 of bottomcover 22, and through keyway space 35, until the proper amount (about A)of end 16 projects from end 19'. Then tubing 16 is wound in the spacesbetween helixes 20 on core 19, and finally around slot edge 36 of topcover piece 23, and into keyway 36 A short length 11 (about A") of thetubing will project beyond the upper end of core. 19. Finally, piece 27of cover 21 is slipped over core 19 by sliding key 28 over the tubing inkeyway 30, so that end 11 of the tubing is safely locked in space 31 ofthe keyway.

Mold 18, with coil 19 mounted thereon, now is ready for baking, This isdone by placing the assembly in a baking oven for 1 to 1.1 hr. at 375390F. This temperature is higher than the recommended specificationtemperature for safe usage of the resin, and some incipient softeningtakes place accompanied by a stabilization of the coil shape. However,there is no collapse of the tubing from the original roundcross-sectional shape, due, in a great part, to the supporting eifort offins 20. After the specified baking is completed, the assembly isremoved from the oven and allowed to cool. Then, end 22 and piece 27 areSlipped off the ends of core 19, and coil is unwound from helix 20.

It will be noted that stabilization of the coil shape apparently takesplace at the incipient softening temperature of the plastic, whichtemperature is about 90 to 100 F. higher than the recommended safeoperating tempera- 2 ture for continuous use of the resin. Although around core 19 is disclosed herein, it is to be understand that cores ofother shapes may be employed, if desired.

I claim:

1. A mold for making a stable flexible coil with straight ends from astraight length of thermoplastic tubing, comprising a cylindrical core,a continuous helical fin spaced to accommodate one Width of said tubingand having a length about equal to the linear length of the desired coiland height substantially equal to the outer diameter of a tubing to becoiled and disposed around the center portion of said core, a taperedkeyway beginning at the surface of said core near each end of said helixand protruding further into said core and terminating at the end of saidcore below the center thereof, a removable sleeve disposed over one endof said core, a rounded slot cut into the inner edge of said sleeveimmediately over said keyway and far enough to accommodate an end of atubing as it is disposed in said keyway, locking means on said sleevefor lateral locking of said sleeve on said core to prevent sidewisemovement, and a similar removable sleeve disposed on the other end ofsaid core.

2. A mold according to claim 1 in which the similar removable sleeve issplit axially into twopieces, one piece being attachable to said core,and the other piece having lateral locking means coacting with itskeyway to prevent sidewise movement.

3. A mold according to claim 1 in which the locking means on the firstsleeve coacts with its keyway to prevent sidewise movement.

References (Zited in the file of this patent UNITED STATES PATENTS312,590 Tyrell et a1 Feb. 17, 1885 694,220 Webster Feb. 25, 19022,225,026 Welsh Dec. 17, 1940 2,322,757 Ward June 29, 1943 2,363,826Yellin Nov. 28, 1944 2,393,058 Pierce et a1. Jan. 15, 1946 2,478,861Collins et a1. Aug. 9, 1949 2,491,857 Greiner Dec. 20, 1949 2,565,465Arnes Aug. 28, 1951 2,573,300 Beaumariage et al. Oct. 30, 1951 2,586,763Judisch Feb. 19, 1952 2,843,878 Berberich July 22, 1958 2,878,514Nichols et al. Mar. 24, 1959 2,920,351 Hardesty et al Jan. 12, 1960FOREIGN PATENTS 11,078 Great Britain May 4, 1897

1. A MOLD FOR MAKING A STABLE FLEXIBLE COIL WITH STRAIGHT ENDS FROM ASTRAIGHT LENGTH OF THERMOPLASTIC TUBING, COMPRISING A CYLINDRICAL CORE,A CONTINUOUS HELICA FIN SPACED TO ACCOMMODATE ONE WIDTH OF SAID TUBINGAND HAVING A LENGTH ABOUT EQUAL TO THE LINEAR LENGTH OF THE DESIRED COILAND HEIGHT SUBSTANTIALLY EQUAL TO THE OUTER DIAMETER OF A TUBING TO BECOILED AND DISPOSED AROUND THE CENTER PORTION OF SAID CORE, A TAPEREDDEYWAY BEGINNING AT THE SURFACE OF SAID CORE NEAR EACH END OF SAID HELIXAND PROTRUDING FURTHER INTO SAID CORE AND TERMINATING AT THE END OF SASDCORE BELOW THE CENTER THEREOF, A REMOVABLE SLEEVE DISPOSED OVER ONE ENDOF SAID CORE, A ROUNDED SLOT CUT INTO THE INNER EDGE OF SAID SLEEVEIMMEDIATELY OVER SAID KEYWAY AND FAR ENOUGH TO ACCOMMODATE AN END OF ATUBING AS IT IS DISPOSED IN SAID KEYWAY, LOCKING MEANS ON SAID SLEEVEFOR LATERAL LOCKING OF SAID SLEEVE ON SAID CORE TO PREVENT SIDEWISEMOVEMENT, AND A SIMULAR REMOVABLE SLEEVE DISPOSED ON THE OTHER END OFSAID CORE.